https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3548359/#:~:text=Hippocampus%20is%20a%20complex%20brain,of%20neurological%20and%20psychiatric%20disorders.

NCBI: Hippocampus in Health and Disease 

Meditation training may enhance stress resilience via hippocampal structure alterations. This notion comes from the idea that hippocampal atrophy is associated with clinical disorders that involve stress, anxiety, and depression. These clinical disorders may also be associated with problems of concentration and memory. Thus, structural increase in the hippocampus relate to meditation's potential betterment of these clinical conditions.  There may also be structural differences in the hippocampus because of memory reconsolidation.  Many meditative practices place a strong emphasis on re-evaluating past behavioral patterns and default emotional reactions to events. 
The differences in the hippocampus may be due to the region playing a role in seeing past experiences in a new light and allowing for greater flexibility in present behavior.  Structural differences in the hippocampus may be related to the effort involved in re-contextualizing spontaneous thought processes, memories, and simulations during meditation practice.

Hippocampus in meditation

This has a frequency of 3.5 to 7.5 hz and relates to slow activity. It connects to creativity, daydreaming, memory, emotion, sensation, reflection, meditation, and spiritual awareness. It’s the state that lies between being awake and asleep. Theta activity is abnormal in awake adults, but normal in children up to age 13. It reflects activity from the limbic system and hippocampus. If it works properly it can aid in learning.

EEG Theta

Long-term potentiation has been most commonly studied in the hippocampus, more specifically in the Schaffer collateral axons of the ca3 neurons and the ca1 pyramidal cells.

Long-term Potentiation in Hippocampus

Clive Wearing was a highly skilled musician who suffered severe damage to his hippocampus due to an illness. As a direct consequence of this brain injury, he completely lost the capacity to encode and retain any new memories, illustrating the critical role of the hippocampus in memory formation.

Case Study of Clive Wearing

In an experiment to understand the hippocampus's function, researchers created lesions in the hippocampi of rats. These rats subsequently showed impaired memory in various tasks, including object recognition and navigating mazes. The results indicated that the hippocampus is vital for normal recognition memory and spatial memory.

Example of Hippocampus's Role in Memory: Rat Lesion Experiment

The hippocampus plays a crucial role in organizing memories by projecting information to various cortical regions. This process is essential for giving memories their meaning and for establishing connections between different, related memories.

Hippocampus's Role in Connecting and Contextualizing Memories

Injury to the hippocampus, a structure located within the temporal lobes, prevents the processing of new declarative memories. This means that an individual with such damage loses the ability to form new long-term memories for facts and events, a condition exemplified by the famous case of patient H.M.

Effect of Hippocampal Injury on Declarative Memory

Anterograde amnesia is the inability to form new long-term memories following an event like brain trauma, while memories from before the injury remain intact. This condition, often linked to hippocampal damage, disrupts the consolidation of information from short-term to long-term memory. A key characteristic of this amnesia is the differential impact on memory systems: individuals are typically unable to form new episodic (events) or semantic (facts) memories, but they often retain the ability to form new procedural memories (skills).

Anterograde Amnesia

Based on the specific pattern of preserved and impaired abilities described in the case study, which brain structure is most likely damaged? Justify your answer by explaining the distinction between the types of memory demonstrated by the patient.

Analysis of Memory Deficits

Henry Molaison (H.M.) is one of psychology's most famous case studies. In 1953, surgeons removed large sections of his hippocampus to treat severe epilepsy. While the surgery successfully stopped his seizures without affecting his IQ or personality, it left him with anterograde amnesia. His short-term memory remained intact, but he permanently lost the ability to transfer new information into long-term memory—a process known as consolidation. This case was crucial for memory research because it demonstrated a clear dissociation between short-term and long-term memory and highlighted the temporal lobes' essential role in memory consolidation.

Case of Henry Molaison (H.M.)

Key brain structures involved in memory have specific anatomical locations: the prefrontal cortex is situated in the frontal lobe, the cerebellum is at the rear, and the amygdala and hippocampus are located deeper within the brain.

Locations of Memory-Related Brain Structures

The hippocampus, a structure within the temporal lobes, is central to learning and memory. It is essential for consolidating new information into long-term memory, a process that involves transferring new learning for permanent storage. Research has shown its specific involvement in normal recognition memory and spatial memory, as demonstrated in studies where rats with hippocampal lesions showed impairment in tasks like object recognition and maze running. Furthermore, the hippocampus projects information to cortical regions, which helps to give memories meaning and connect them with other memories. It is also critical for contextualized emotional learning. The famous case of patient H.M., who could not form new memories after his hippocampus was removed, provided significant evidence for its role.

Google

Columbia University

Washtenaw Community College

New Mexico Highlands University

University of Georgia

- Hippocampus 
- Temporal lobes 
- Cortex
- Mammillary body 
- Cerebellum 

Relevant Brain Structures and Function: Learning and Memory 

Decreased gray matter concentrations:
- Right hippocampus
- Right dorsal anterior cingulate cortex (ACC)
- Right orbitofrontal cortex (OFC)

Altered activations:
- Left hippocampus
- Parahippocampal gyrus

Disturbances in these emotional processing regions:
- Left ventral ACC
- Dorsal ACC
- Dorsomedial prefrontal cortex
- Left ventrolateral prefrontal
- OFC

Childhood abuse c-PTSD neuroimaging studies: Specific Brain Region Results

Three Main Structures in the Limbic System

Situated on the side of the head near the temples, the temporal lobe is a region of the brain involved with several key functions, including hearing, memory, emotion, and certain language abilities. It houses important structures for these functions, such as the auditory cortex, which processes sound, and Wernicke's area, which is crucial for language comprehension.

Temporal Lobe

Contrary to the earlier belief that memory involves the entire brain, research following Lashley's work has demonstrated that memory functions are localized. Specific brain regions and even individual neurons play key roles in forming memories. The primary structures identified as crucial for memory are the amygdala, the hippocampus, the cerebellum, and the prefrontal cortex.

Key Brain Structures Involved in Memory

Wang, P. P., & Jernigan, T. L. (1994). Morphometric studies using neuroimaging. Neurologic clinics, 12(4), 789–802.

Morphometric studies using neuroimaging. 

https://commons.wikimedia.org

This is a repository of free electronic media.

Wikimedia Commons

Spielman, R. M., Jenkins, W. J., & Lovett, M. D. (2020, April 22). Psychology (2nd ed.). OpenStax. https://openstax.org/books/psychology-2e/pages/1-introduction

OpenStax Psychology (2nd ed.) Textbook

Hippocampus

The orbitofrontal cortex is connected to primary sensory regions and the  limbic system, including the amygdala, striatum, and hypothalamus. The orbitofrontal cortex is essential for understanding the precise relationship between stimuli and motivational outcomes. It may generate more flexible assessments of stimuli and experience. The orbitofrontal cortex is also implicated in emotion regulation, specifically down-regulating and reappraising negative emotional states. This regulatory function may be part of a broader role for the orbitofrontal cortex in the self-monitoring and integration of cognitive and emotional cues in decision-making. 

Orbitofrontal Cortex

The anterior cingulate cortex and the mid-cingulate cortex may be involved in the general process of ‘self-regulation’. This region is crucial for self-control, focused problem-solving, and adaptive behavioral responses under changing conditions.  Therefore, the anterior cingulate cortex and mid-cingulate cortex may be important when the value of actions is uncertain or changing, and when multiple pieces of information must be considered to discern the optimal behavioral response. The anterior cingulate cortex and the mid-cingulate cortex have a role in decision-making and adaptively selecting actions based on anticipated outcomes; these regions are activated during reward processing, conflict monitoring, error detection, and pain. 

The anterior cingulate cortex and the 
mid-cingulate cortex

The amygdala is a key brain structure that plays a central role in processing and relaying emotional information, making it a major focus of research into the biological basis of emotions like fear and anxiety. It is composed of various subnuclei and has a crucial role in memory, influencing how memories are stored—a process affected by stress hormones—and is involved in memory consolidation, the transfer of new learning into long-term memory. This is facilitated by enabling a deeper level of memory encoding for emotionally arousing events.

Amygdala

The hypothalamus is a brain structure that regulates various homeostatic processes, including blood pressure, appetite, and body temperature. It serves as an interface between the nervous system and the endocrine system, and it controls the hormonal secretions of the pituitary gland. Furthermore, it is involved in regulating sexual behavior and motivation.

Hypothalamus

Match each of the following brain structures to its primary function.

Located in the fusiform gyrus on the underside of the temporal lobe. When damaged, people can get prosopagnosia (inability to recognize faces).

Fusiform face area (FFA)

Among many theories, there is consensus surrounding the understanding that medial temporal lobe damage only harms certain types of memory and learning, leaving repetition priming, classical conditioning, and reinforcement-learning largely untouched. Many models also agree about organization of the medial temporal lobe.

Consensus About the Medial Temporal Lobe Among Memory Theories

Located at the bottom of the temporal lobe. It likely plays a major role in our ability to generate meaning from sensory input and affects our understanding of many topics.

Anterior Temporal Lobe (ATL)

The following areas of brain lobes can be considered when implementing neurofeedback:

- Parietal lobes
- Frontal lobes
- Temporal lobes
- Occipital lobes
- Sensorimotor cortex
- Cingulate gyrus
- Broca's area
- Left hemisphere
- Right hemisphere

Brain Lobe Considerations When Using Neurofeedback

Conditions associated with the temporal lobes include:

- Anger
- Rage
- Dyslexia
- Long-term memory
- Closed head injury 

Temporal Lobes Associated Conditions

Located in the temporal lobe, the auditory cortex is the primary brain region for processing auditory information. It serves as the final destination in the main auditory pathway, receiving neural signals that have been relayed through the inferior colliculus and the medial geniculate nucleus of the thalamus.

Auditory Cortex

Located within the temporal lobe, Wernicke's area is a critical region for the comprehension of speech. Damage to this area can result in a specific type of language deficit where an individual can still produce sensible-sounding language but loses the ability to understand what is being said.

Wernicke's Area

Based on the patient's symptoms, which major region of the brain, located on the side of the head, is most likely damaged? Explain your reasoning by connecting specific symptoms to the known functions of this region.

Clinical Symptom Analysis

A part of the frontal lobe that is responsible for higher-level cognitive functioning and focuses on "in the moment" or rash behavior (decision-making, problem solving, and so on). This area is also responsible for the development of personality. The PFC has a handful of (not universally agreed upon) subdivisions:

- Dorsomedial
- Dorsolateral
- Ventromedial
- Ventrolateral
- Orbitofrontal

Prefrontal Cortex (PFC)

The cerebellum, a hindbrain structure known as the 'little brain,' governs balance, coordination, and motor skills. It also plays a critical role in processing and storing implicit memories. This includes procedural memory for tasks, motor learning, and classical conditioning. Consequently, damage to the cerebellum can impair the ability to learn conditioned responses.

Cerebellum

The dentate gyrus is a structure within the hippocampus that aids in the processing of memory.

The Dentate Gyrus

The entorhinal cortex acts similarly to a gateway in the brain, allowing information to enter and exit the memory processing area of the brain, the hippocampus.

Entorhinal Cortex

Neurons are specialized cells located in the nervous system that send information between different parts of the body and the brain.

Neurons

Several key neurotransmitters, including epinephrine, dopamine, serotonin, glutamate, and acetylcholine, are understood to be involved in memory processes. While the precise function of each neurotransmitter is still a subject of ongoing research and debate, it is established that the communication between neurons facilitated by these chemicals is fundamental for the formation of new memories.

Role of Neurotransmitters in Memory

The cerebellum's primary function in memory is the processing of procedural memories, which are the memories for skills and routine actions.

Role of the Cerebellum in Memory

The hippocampus serves a critical function in memory as the primary site where new memories are encoded.

Role of the Hippocampus in Memory

The amygdala influences memory by helping to determine which pieces of information are stored as memories. This process is guided by the strength of the emotional response associated with an event.

Role of the Amygdala in Memory

A patient is involved in a car accident and sustains a localized brain injury. After the accident, they are unable to form new long-term memories of events or facts, such as what they ate for breakfast or the name of their new doctor. However, they can still recall memories from their childhood and can learn new physical skills, like a new dance routine, with practice. Their emotional responses to events seem normal. Based on this information, which brain structure is most likely to have been damaged, and why?

Learn Before

Related

Learn After